1. Field of the Invention
This invention relates generally to a system and method for detecting the absence of contact between the hands of a driver of a vehicle and a steering wheel of the vehicle and, more particularly, to a system and method for detecting a condition when the driver's hands are off the steering wheel of a vehicle to maintain attentiveness of the driver and ensure proper functioning of various steering actuators.
2. Description of the Related Art
The automobile industry has been making constant efforts to enhance comfort and safety of the occupants of a vehicle, especially the driver. These endeavors have resulted in the birth of technologies such as advanced driver assistance systems (ADAS) and electronic stability control (ESC) systems. Some of the features of ADAS are adaptive cruise control systems, lane assist systems and driver assist steering systems. ESC systems, on the other hand, use computerized technologies that improves vehicle handling by detecting and preventing unstable conditions.
One of the above-mentioned features of the ADAS, the driver assist steering system or the active front steering system, hereinafter used interchangeably, is a complementary system for a front-steered vehicle that adds or subtracts a component to the angular movement of the steering wheel in order to reduce the driver effort required to rotate the steering wheel or augment the driver steering for improved vehicle safety and stability. The resulting steering angle is thus composed of the steering input by the driver and the component contributed by the steering system.
ADAS and ESC systems aid the driver by reducing the driving burden. However, it is not desirable to reduce the driver's vigilance and attentiveness, even when such systems are exercising some or most of the control over the vehicle. It is generally imperative that the driver puts his/her hands on the steering wheel, and be ready to takeover the steering control whenever the situation demands. Further, various steering actuators used in an active front steering systems function properly only when the driver has his hands on the steering wheel while the vehicle is in motion.
Moreover, detection of a no-contact condition between the driver's hands and the steering wheel of the vehicle can act as an alarm for the various human machine interface friendly ADAS and ECS systems prompting them to kick in and take over the control of the vehicle.